Universal-headed hammer



April 25, 1961 MCRAE 2,981,177

UNIVERSAL-HEADED HAMMER 2 Filed July 21, 1958 2 Sheets-Sheet 1 l9 was so 58 34 32 INVENTOR.

DU NCAN G. M RAE Wad 197 7 DRIVE);

April 25, 1961 i MCRAE 2,981,177

UNIVERSAL-BEADED HAMMER Filed July 21, 1958 2 Sheets-Sheet 2 INVENTOR.

DUNCAN G. M RAE UNIVERSAL-HEADER) HR Duncan G. McKee, 3569 E. Georgia St., Vancouver, British Columbia, Canada Filed July 21, 1958, Ser. No. 749,372

' 6 "Claims. Cl. 101-28) This invention relates to a hammer having a head so mounted as to be able to swing universally, that is, in all directions relative to an axis normal to the striking surface of the head when the latter is in its usual position.

This hammer is primarily designed for impressing indicia into wood surfaces, but the indicia may be omitted in order that the hammer may be used for other purposes.

The equipment now in common use for stamping marks or symbols on log surfaces, usually the ends thereof, consists of ordinary hammers having the marks or symbols projecting from the end thereof. If the end of the hammer is not parallel with the log surface when the blow is struck, the indicia are not properly impressed in the log surface. In logging, a high percentage of the marks or symbols on the logs are not distinguishable.

An object of the present invention is the provision of a hammer having a head that when a blow against a surface is improperly aimed, will adjust itself so that the striking face moves into position substantially parallel with said surface.

Another object is the provision of a hammer having a head mounted for universal swinging action with the centre of the swing located within the head but spaced well back from the striking face thereof.

Another object is the provision of a hammer having a universal head which may be quickly and easily mounted on and demounted from the hammer so that the latter may be quickly assembled in the first place, and the head may be easily changed. This feature is particularly useful when the hammer is used for stamping indicia on logs or other objects since if it is necessary to change the indicia, thismay be quickly and easily done merely by changing the head.

A hammer according to the present invention comprises a shank having a ball secured to an end thereof aligned therewith on its longitudinal axis. A head for the hammer has a socket formed therein and opening out through the inner end or surface thereof and in which the ball movably fits. The head includes means for retaining the ball in the socketwhile permitting it to swing universally around said ball. Spring means on the shank bears against the inner surface of the head to urge the latter outwardly from the shank and normally retains the outer or striking surface of the head substantially normal to the longitudinal axis of the shank. It is preferable to provide an annular shoulder on the shank spaced from the head, said shoulder being engageable by the head when the latter is swung a predetermined distance around the ball in any direction to limit said swinging movement. In most cases, the shank is secured to and projects outwardly from an end of a body that supplies the main weight for the hammer. It is also desirable, although not absolutely necessary, to removably mount the head 'on the ball.

A preferred form of the invention is illustrated in the accompanying drawings, in which,

Figure 1 is a side elevation of the hammer,

, 2,981,177 Patented Apr. 25, 1961 ice Figure 5 is an elevation of the striking head looking I at the inner end or surface thereof and turned to a position ready to be moved on to the ball shown in Figure 4,

Figure 6 is an exploded view showing the hammer shank and ball in plan, and the head in section in position to be moved on to the ball, L

Figure 7 is a view similar to Figure 6 but with the head part way on to the ball,

Figure 8 is a vertical section taken on the line 88 of Figure 7 and Figure 9 is an elevation of the hammer just after a blow has been struck with the head swung so that its outer surface is substantially parallel with the surface of the object being struck, said surface being inclined relative to the general direction of the blow.

Referring to the drawings, 10 is a universal-headed hammer including a shank 11 having an outer end 12. Although this shank may be mounted directly on a hammer handle, it is usually preferable to provide a weight body 15 of generally cylindrical form. In this case, shank 11 projects outwardly from end 16 of the body centrally thereof. A hammer handle 19 is connected to the body in any convenient manner. In this example, a hole 21 extends through the hammer body, and the outer end of the handle fits into this hole so that the handle projects outwardly from the body substantially at right angles thereto.

A ball 25 is secured to end 12 of the shank and is aligned with the latter. In other words, the ball is on the longitudinal axis 26 of the shank, see Figure 2. This shank axis actually passes through the centre of the bfll. It is preferable to provide an annular shoulder, 28 on the shank. This may be formed by bevelling the shank end, as shown.

A head 32 is movably mounted on ball 25. This head has inner and outer surfaces 34 and 35, the latter preferably being substantially flat, and normally lying in a plane at right angles to the shank axis26. If the device is used for hammering purposes, this surface 35 would be the striking surface. However, when the hammer is used for stamping purposes, a face plate 38 lies over surface 35 and is secured thereto, said face plate carrying the required indicia 39 projecting outwardly therefrom.

The head 32 is formed with a socket 42 therein that opens out at 43 through the inner surface 34 therof. It will be noted from Figure 2 that most of the ball fits within the socket, and the socket is shaped slidably to fit around the ball surface. The head surface 34 is spaced from the annular shoulder 28 and the outer end 12 of shank 11 so that the head is free to swing universally around the ball.

Means is provided on head 32 for retaining the ball 25 in socket 42 while permitting the head to swing universally therearound. Furthermore, it is desirable removably to mount the head on the ball so that if other indicia are required, another head having said indicia attached thereto may be substituted for the one on the hammer.

One or more flanges 46 is or are formed on the head at the inner surface 34 thereof and extend into the socket opening 43 towards the shank axis 26. In the preferred form of the invention, there are two of these flanges, one opposed to the other, as clearly shown in Figure 5. These flanges are produced when socket 42 is formed in the head. It will be noted from Figure 2 that the entrance 43 of the socket is of smaller diameter than the full diameter of the socket and the ball. This means that the flanges 46 fit against the ball in a plane located to one side of the major diameter of said ball. The two illustrated flanges as are formed by cutting opposed notches 48 in the inner end of the hammer head at the entrance 43 thereof.

With the flange construction just described, ball 25 is formed with a groove 52 for each flange and extending substantially parallel with shank axis 26. In this example, there are two grooves 52 opening outwardly from opposite sides of the ball.

'In order to assemble hammer 10, head 32 is positioned with its socket 42 facing ball 25, and with flanges 46 aligned with the ball grooves 52, see Figures 6 and 7. As the head is moved in the direction of arrow 54- in these figures, the flanges move through the grooves. Figure 7 illustrates the head partially on the ball. When the head has been moved as far as it can go, it is rotated around axis 26 to move flanges .46 out of line with the ball grooves, at which time said flanges bear against the ball surface behind the major diameter of the ball so that the head cannot be moved outwardly axially from the ball, and yet the head may swing universally around the ball, the only limitation of this movement being created by shoulder 28 when it is engaged by the inner end of the head. The bevel of this shoulder is such that when the surface 34 of the head engages the shoulder, it is bearing against a flat surface.

Spring means is provided on the shank which bears against the inner surface of the head and urges said head outwardly from the shank and normally retains the outer head surface substantially normal to the axis 26. Although a resilient sleeve may be used for this purpose, it is preferable to employ a coil spring 58 which surrounds the shank and bears against the inner surface of the head. It is preferable to use a conical spring with the larger end thereof bearing against the hammer head. This spring may also be used to keep head 32 from rotating around the shank axis during use. This is accomplished by providing the spring with prongs 6t and 61 projecting axially from the opposite ends thereof and removably fitting respectively in corresponding sockets 63 and 64- formed in the adjacent end of body 15 and the inner end of head 32. Prong 60 is preferably arranged l80 around the spring from prong s1. These prongs and their respective sockets are also arranged so that when the spring is in its normal at-rest position, the head is locked on the ball by shoulders or flanges 46. In order to release the head, it is only necessary to rotate it around shank axis 26 until the flanges are aligned with ball grooves 52, this rotating being done'against the pressure of the spring, or if desired, one of the spring prongs may be pried out of its socket in order to permit this rotation of the head. When the head is drawn outwardly from the ball, prong 61 comes out of its socket 64 to separate the spring from the head.

Figure 9 illustrates hammer 10 just after a blow has been directed against the surface 63 of an object 76, such as a log. The hammer has not been swung so that the striking surface thereof is parallel to the log surface where the impact takes place. At the moment of first impact, surface 68 was inclined relative to the outer surface 35 of head 32. Therefore, the head swung around ball 25 until its outer surface was substantially parallel with the log surface 68. During this time, the indicia 35 were forced into the Wood to impress the mark or symbol therein. It will be noted that head 32 is lying at an angle to shank axis 26. Spring :33 which normally holds the head in its proper position, permits this swinging action to take place by compressing a little on one side thereof. It will be noted that the maximum swinging action is attained when the inner surface 34 of the head engages annular shoulder 28 on the shank.

The ideal way is to have the full force of the blow moving along the shank axis at the time the indicia engaged the wood surface, and this takes place if said surface and the outer surface of the head are substantially parallel. However, some of the force of the blow is lost relative to moving indicia into the wood, when the head has swung out of its normal position, as in Figure 9. However, the maximum effect is attained under these circumstances with the present hammer because of the fact that the fulcrum or pivot of the head coincides with the center of the ball, and this center is spaced rearwardly some distance from the striking surface of the head. No matter which way the head swings, the effective force of the blow is the same.

What I claim as my invention is:

1. A universal-headed hammer comprising a shank, a ball larger than and secured to an end of the shank aligned with the latter on the longitudinal axis thereof, a head having inner and outer surfaces, a socket formed in the head and opening out through the inner surface thereof in which most of the ball movably fits, said socket being of such size and shape as just slidably to fit around the ball, at least one groove formed in the ball and extending substantially parallel with the shank axis, a flange for each groove formed on the head at the inner surface thereof and extending into the socket opening towards the shank axis, said flange being shaped to move through the ball groove when the head is moved on to the ball and overlapping the ball when the head is rotated around the shank axis to retain said head on the ball while permitting the head to swing universally around said ball, and resilient means on the shank fixed at one end thereto and hearing at its opposite end against the inner surface of the head urging said head outwardly from the shank and normally retaining the outer head surface substantially normal to the longitudinal axis of the shank.

2. A universal-headed hammer comprising a shank, a ball larger than and secured to an end of the shank aligned with the latter on the longitudinal axis thereof, a head having inner and outer surfaces, a socket formed in the head and opening out through the inner surface thereof in which most of the ball movably fits, said socket being of such size and shape as just slidably to fit around the ball, at least one groove formed in the ball and extending substantially parallel with the shank axis, a flange for each groove formed on the head at the inner surface thereof and extending into the socket opening towards the shank axis, said flange being shaped to move through the ball groove when the head is moved on to the ball and overlapping the ball when the head is rotated around the shank axis to retain said head on the ball while permitting the head to swing universally around said ball, and resilient means on the shank fixed at one end thereto and removably connected at its opposite end to the head to prevent rotation of the head around the shank axis and normally retaining the outer head surface substantially normal to the longitudinal axis of the shank.

3. A universal-headed hammer comprising a body, a handle connected to the body and extending outwardly substantially at right angle thereto, a shank projecting from an end of the body, said shank having an outer end spaced from the body, a ball larger than and secured to the outer end of the shank aligned with the latter on the longitudinal axis thereof, a head having inner and outer surfaces, a socket formed in the head and opening out through the inner surface thereof in which most of the ball movably fits, said socket being of such size and shape as just slidably to fit around the ball, at least one groove formed in the ball and extending substantially parallel with the shank axis, a flange for each groove formed on the head at the inner surface thereof and extending into the socket opening towards the shank axis, said flange being shaped to move through the ball groove when the head is moved on to the ball and overlapping the ball when the head is rotated around the shank axis to retain said head on the ball while permitting the head to swing universally around said ball, and resilient means on the shank bearing at one end against the body and at the opposite end against the inner surface of the head urging said head outwardly from the shank and normally retaining the outer head surface substantially normal to the longitudinal axis of the shank.

4. A universal-headed hammer comprising a body, a handle connected to the body and extending outwardly substantially at right angles thereto, a shank projecting from an end of the body, said shank having an outer end spaced from the body, a ball larger than and secured to the outer end of the shank aligned with the latter on the longitudinal axis thereof, a head having inner and outer surfaces, a socket formed in the head and opening out through the inner surface thereof in which most of the ball movably fits, said socket being of such size and shape as just slidably to fit around the ball, at least one groove formed in the ball and extending substantially parallel with the shank axis, a flange for each groove formed on the head at the inner surface thereof and extending into the socket opening towards the shank axis,

said flange being shaped to move through the ball groove when the head is moved on to the ball and overlapping the ball when the head is rotated around the shank axis to retain said head on the ball while permitting the head to swing universally around said ball, and a coil spring surrounding the shank and bearing at one end against the body and removably connected at its opposite end to the head to prevent rotation of the head around the shank axis and normally retaining the outer head surface substantially normal to the longitudinal axis of the shank.

5. A universal-headed hammer comprising a body, a handle connected to the body and extending outwardly substantially at right angles thereto, a shank projecting from an end of the bod said shank having an outer end spaced from the body, a ball larger than and secured to the outer end of the shank aligned with the latter on the longitudinal axis thereof, a head having inner and outer surfaces, a socket formed in the head and opening out through the inner surfaces thereof in which most of the ball movably fits, said socket being of such size and shape as just slidably to fit around the ball at least one groove formed in the ball and extending substantially parallel with the shank axis, a flange for each groove formed on the head at the inner surface thereof and extending into the socket opening towards the shank axis, said flange being shaped to move through the ball groove when the head is moved onto the ball and overlapping the ball when the head is rotated around the shank axis to retain said head on the ball while permitting the head to swing universally around said ball, and a coil spring surrounding the shank and bearing at its opposite ends against the body and the inner surface of the head, and prongs projecting axially from the opposite ends of the spring and removably fitting in corresponding sockets formed in the adjacent body end and the head, said spring preventing rotation of the head around the shaft axis and normally retaining the outer head surface substantially normal to the longitudinal axis of the shank.

6. A universal-headed hammer as claimed in claim 5 including an annular bevelled shoulder formed on the shank end where the fall is connected to said end and Within the spring and spaced from the inner surface of the head, said shoulder being bevelled to present a flat surface to the inner surface of the head when said head is swung around the ball in any direction to limit said swinging movement.

References Cited in the file of this patent UNITED STATES PATENTS 902,436 McFarland Oct. 27, 1908 983,153 Lowe et al. Jan. 31, 1911 990,719 Fisher Apr. 25, 1911 1,061,862 Molt May 13, 1913 1,104,564 Snyder July 21, 1914 1,475,865 Peters Nov. 27, 1923 2,282,932 Burnett May 12, 1942 2,469,425 Anderson May 10, 1949 2,491,295 Anderson Dec. 13, 1949 2,859,710 Elsner Nov. 11, 1958 

